The Gynecologic Oncology Group (GOG) was founded Februrary 20, 1970, as a cooperative group of institutions represented by gynecologists, radiotherapists, medical oncologists and related specialists for conducting clinical trials involving all accepted and experimental treatment methods in a large number of patients with all types of gynecologic cancer. Currently the Group is composed of 33 participating institutions in the United States with a combined yearly new gynecologic cancer load of approximately 2600. There are 20 active study protocols with 2003 cases entered as of December, 1974. Of these patients, 498 were entered during the previous 6 months, which makes for an acquisition rate of approximately 1000 per year. Several new protocols are being considered which would increase the acquisition rate even more. The GOG Pathology and the GOG Radiotherapy Repositories have been established and have been functioning as of May, 1973 to allow for periodic review of histologic slides and radiotherapeutic calculations for all GOG study patients. The reviews are carried out by pathologists and radiotherapist members of the Group. An Endocrinology Laboratory has been established to perform assays for gonadotropins, estrogens and testosterones on patients with rare ovarian tumors. The University Gynecologic Oncology Service was established in 1970 and is centered in the Buffalo General Hospital and functions in affiliation with other University-associated hospitals. This service has participated in the GOG since its inception as a unit with Roswell Park Memorial Institute. The University Service (Buffalo General Hospital) has registered 148 cases with the GOG during the last year. It has participated in all study protocols of the GOG Group and has entered a total of 91 cases into these studies which is above average for all GOG member institutions. Patient studies are carried out under the supervision of the Principal and Senior Investigators.